If this is the only condition to be tested, then you must retrieve every record in the file and apply the condition.

Code:

READ file PHYSICAL
IF field-name <> 'value'
THEN
ESCAPE TOP
END-IF

Code:

READ file PHYSICAL
ACCEPT IF field-name = 'value'

Code:

READ file PHYSICAL
WHERE field-name = 'value'

WHERE is more efficient than ACCEPT which is more efficient than IF.

If your DBA allows it (highly unlikely - I wouldn't recommend it), the field could be defined in the DDM for non-descriptor searches. In this case Adabas would read every record in the file, but return only those that satisfy the condition.

Code:

READ file BY field-name FROM 'value' TO value'

The best scenario would see a descriptor range narrow the number of records to be retrieved, then apply the condition.